Although the power line was depicted on the chart in the WAS, and the pilot had been briefed about the hazard presented by power lines in the company's area of operations, it was not determined whether the pilot knew the location of this specific power line. The power line was installed over the channel almost 50years ago by a private owner, before the utility company assumed ownership of the circuit. No record was found of any TC evaluation of the power line. Therefore, the power line was likely never assessed to determine whether it constituted a hazard to aviation safety, and TC did not require the owner of the power line to install markers to indicate its presence. The power line was invisible unless viewed at close range with knowledge that it was there. Additionally, the poles supporting the power line were hidden from view by trees. The pilot likely did not see the power line before the aircraft struck it. The pilot's task was to fly at the normal cruise altitude of 1000 to 2000feet above ground level to a lake 15miles from his departure point. He had no operational reason to be flying at a low altitude over Sabaskong Bay. The engine was operating at a steady, high-power setting, indicating that the pilot was not making a precautionary landing on the water. The pilot might have recognized the boat operated by his co-worker, made a low pass toward the boat, and, just before striking the wire, started to climb and turn left to follow the channel around the peninsula. The Standards Obstruction Markings Manual indicates that the Minister of Transport is responsible for assessing obstructions to determine if they are likely to constitute a hazard to air navigation and, consequently, to require marking. However, the manual states that the Minister may perform an aeronautical evaluation, indicating that there is some discretion in deciding whether to exercise the responsibility to assess obstructions. As a result, some obstructions, such as the wire in this occurrence, might not have been assessed and, consequently, were not marked.Analysis Although the power line was depicted on the chart in the WAS, and the pilot had been briefed about the hazard presented by power lines in the company's area of operations, it was not determined whether the pilot knew the location of this specific power line. The power line was installed over the channel almost 50years ago by a private owner, before the utility company assumed ownership of the circuit. No record was found of any TC evaluation of the power line. Therefore, the power line was likely never assessed to determine whether it constituted a hazard to aviation safety, and TC did not require the owner of the power line to install markers to indicate its presence. The power line was invisible unless viewed at close range with knowledge that it was there. Additionally, the poles supporting the power line were hidden from view by trees. The pilot likely did not see the power line before the aircraft struck it. The pilot's task was to fly at the normal cruise altitude of 1000 to 2000feet above ground level to a lake 15miles from his departure point. He had no operational reason to be flying at a low altitude over Sabaskong Bay. The engine was operating at a steady, high-power setting, indicating that the pilot was not making a precautionary landing on the water. The pilot might have recognized the boat operated by his co-worker, made a low pass toward the boat, and, just before striking the wire, started to climb and turn left to follow the channel around the peninsula. The Standards Obstruction Markings Manual indicates that the Minister of Transport is responsible for assessing obstructions to determine if they are likely to constitute a hazard to air navigation and, consequently, to require marking. However, the manual states that the Minister may perform an aeronautical evaluation, indicating that there is some discretion in deciding whether to exercise the responsibility to assess obstructions. As a result, some obstructions, such as the wire in this occurrence, might not have been assessed and, consequently, were not marked. The power line running overhead the channel was invisible, except at very short range, and was not marked to indicate its presence. The pilot was flying at a very low altitude and likely did not see the power line.Findings as to Causes and Contributing Factors The power line running overhead the channel was invisible, except at very short range, and was not marked to indicate its presence. The pilot was flying at a very low altitude and likely did not see the power line. The Standards Obstruction Markings Manual allows for discretion in deciding whether to assess obstructions, making it possible for some obstructions to not be assessed and, consequently, to not be marked.Findings as to Risk The Standards Obstruction Markings Manual allows for discretion in deciding whether to assess obstructions, making it possible for some obstructions to not be assessed and, consequently, to not be marked. Since this accident, the aircraft operator has posted notices in its operations room, stating that low flying and disregard of the Canadian Aviation Regulations will not be tolerated and that pilots are prohibited from flying to a location other than to where they are dispatched. When the operator dispatches pilots to a remote location, they will continue their current practice of briefing pilots on the location of wires and recommending specific areas for landing and take-off. The operator is planning to enhance training to emphasize the hazard presented by power lines. TC regularly promotes safety awareness on the hazards of low flying through seminars and other promotional material such as the Take-five brochures and recurring wire-strike articles in safety newsletters. TC has advised the Transportation Safety Board of Canada that, notwithstanding the discretionary wording of section 2.3 of the Standards Obstruction Markings Manual, all obstructions reported to TC are assessed. Additionally, a Notice of Proposed Amendment (NPA) has been issued for CAR 601.19 that will require proponents to advise TC of new construction, of modifications to an existing structure or of the launching of large moored balloons or kites. This requirement should ensure TC is informed of potential hazards to aviation and enable the department to perform the appropriate assessments. The owner of the power line is planning, during 2002, to assess all its power line crossings on Lake of the Woods, of which Sabaskong Bay is a part, to ensure that they meet standards. Crossings that do not meet standards will be assessed for upgrading or replacement.Safety Action Since this accident, the aircraft operator has posted notices in its operations room, stating that low flying and disregard of the Canadian Aviation Regulations will not be tolerated and that pilots are prohibited from flying to a location other than to where they are dispatched. When the operator dispatches pilots to a remote location, they will continue their current practice of briefing pilots on the location of wires and recommending specific areas for landing and take-off. The operator is planning to enhance training to emphasize the hazard presented by power lines. TC regularly promotes safety awareness on the hazards of low flying through seminars and other promotional material such as the Take-five brochures and recurring wire-strike articles in safety newsletters. TC has advised the Transportation Safety Board of Canada that, notwithstanding the discretionary wording of section 2.3 of the Standards Obstruction Markings Manual, all obstructions reported to TC are assessed. Additionally, a Notice of Proposed Amendment (NPA) has been issued for CAR 601.19 that will require proponents to advise TC of new construction, of modifications to an existing structure or of the launching of large moored balloons or kites. This requirement should ensure TC is informed of potential hazards to aviation and enable the department to perform the appropriate assessments. The owner of the power line is planning, during 2002, to assess all its power line crossings on Lake of the Woods, of which Sabaskong Bay is a part, to ensure that they meet standards. Crossings that do not meet standards will be assessed for upgrading or replacement.